Triangular cartons



Aug. 15, 1961 L. A. WHEELER TRIANGULAR CARTONS Filed Dec. 7, 1959 2Sheets-Sheet l INVENTOR/ LEONARQ AI HUI WHEELEE Aug. 15, 1961 L. A.WHEELER TRIANGULAR CARTONS 2 Sheets-Sheet 2 Filed Dec. '7, 1959INVENTOIL, LEONAKQ A HUI WHEELE BY ATTORIZI EYS United States Patent2,996,234 TRIANGULAR CARTONS Leonard A. Wheeler, 209 Pinewood Trail,Port Credit, Ontario, Canada Filed Dec. 7, 1959, Ser. No. 857,811 8Claims. (Cl. 229-22) This invention relates to triangular cartons. Moreparticularly the invention relates to a blank from which triangularcartons can be made, methods of assembling the blank to form cartons,and the resulting carton-s which are of triangular cross-section whenerected and are made in a flattened condition so that they may beshipped in their flattened condition and easily erected by the user.

Collapsible triangular cartons are already known but it is believed thatall such cartons as are known suffer from one or both of the followingdisadvantages. The first disadvantage is that no method has heretoforebeen developed for assembling the cartons on such automatic machinery,e.g., right-angled gluers, as are conventional in the art; the cartonshave thus been assembled by hand which is slow and expensive. The seconddisadvantage is that the bottom of the carton, whichhas been arranged tocome into position automatically as the carton is erected from itsflattened condition, has not been provided with any locking means sothat the bottom has had a tendency to move into the interior of thecarton after the latter has been erected. Since the bottom is used tohold the carton in its erected position it is obviously desirable thatthe bottom should be locked in position when the carton is erected.

One of the objects of the invention is to provide a carton of triangularcross-section which may be shipped and stored in a flattened conditionand which is arranged so that one end thereof is locked in position whenthe carton is erected from its flattened condition.

A further object of the invention is to provide a blank from which sucha carton may be assembled.

A still further object of the invention is to provide a method wherebycollapsible triangular cartons may be assembled by fully automaticmachinery such as rightangled gluers.

The invention will be described by way of example with reference to theaccompanying drawings, inwhich:

FIGURE 1 is a plan view of a blank according to the invention for makinga triangular carton,

FIGURES 2, 3 and 4 show consecutive stages in the assembly of the blankof FIGURE 1,

FIGURE 5 is a perspective view of the carton resulting from the blank ofFIGURE 1 and the stages of FIG- URES 2 to 4 as it is being erected,

FIGURE 6 is a perspective view of the carton of FIG- URE 5 fully erectedand partly broken away to show the locking arrangement of the cartonbottom,

FIGURE 7 is a view similar to FIGURE 3 showing a corresponding stage ina modified method of assembling the blank of FIGURE 1, and

FIGURE 8 is a perspective view of a carton resulting from said modifiedmethod.

Referring now to FIGURE 1, the carton blank comprises a sheet ofpaperboard or the like cut and scored to provide a first side wallportion 10 defined by scores 11 and 12; a second side wall portion 13defined by scores 12 and 14; and a third side wall portion 15. Thefirst, second and third side wall portions are arranged in seriateside-by-side relation. A glue tab 16 is integral with the first sideWall portion 10 and the latter is bisected by a score 17 parallel to itslength to provide two equal panels 10a and 10b.

A first end flap 18 extends from one end of the second side wall portion13. The end flap comprises an equilateral, triangular part 19 having asbase a score 20 at "ice the end of the second side wall portion.Springing from an edge of the triangular part 19 is a first extension 21adjacent to the apex of the triangular part; the extension 21 and thepart 19 are separated by a score 22. It will be noticed that the firstextension 21 is on the edge of the triangular part 19 remote from theglue tab 16. A second extension 23 extends from the other edge of thetriangular part 19 and is separated from the latter by a score 24.

A second end flap 25 extends from the third side wall portion 15 and isscored along a line 26 which lies at an angle or of substantially 30 tothe end of the third side wall portion 15 defined by the score 27. Thescore 26 divides the second end flap 25 into an inner portion 28 lyingbetween the score lines 26 and 27 and an outer portion 29. The secondend flap is cut away at 30- for a purpose which will hereinafter bedescribed.

The glue tab 16 is provided, at its end adjacent to the end flaps 18 and25, with a recess indicated generally at 31 which is defined by aninclined edge 32 and a straight edge 33. As will be describedhereinafter, the straight edge 33 mates with an edge 34 on the firstextension 21 and the inclined edge 32 of the recess 31 mates with anedge 35 on the first extension 21.

The end flaps 25, 18 are designed to close one end of the cartonautomatically as. the carton is erected and as will hereinafter bedescribed. The construction of flaps at the other end of the carton doesnot form part of the present invention and therefore no flaps have beenshown in the drawings. It will be understood by one skilled in the artthat any convenient top closure can be employed or it can be omitted ifdesired.

In the assembly of the blank to form the carton, the initially flatblank as shown in FIGURE 1 is passed along a first straight line path inthe direction of the arrow 36. While the blank is passing along thisfirst straight line path, the end flaps 18 and 25 are folded to overliethe second and third side wall portions 13 and 15 respectively.Furthermore, the outer portions 29 of the second end flap 25 is foldedalong the score 26- to overlie the inner portion 28 of the second endflap. At the end of the passage of the blank along the first straightline path, the blank has assumed the form shown in FIGURE 2.

The blank in the form shown in FIGURE 2 is then passed along a secondstraight line path in the direction of the arrow 37; the second path isperpendicular to the first path. As the blank passes along the secondstraight line path, the first side wall portion 10 is folded about thescore 17 so that the panel 10a is caused to overlie the panel 10b and sothat the glue tab 16 partially overlies the second extension 23 and thetriangular part 19 as shown in FIGURE 3. After this fold has been made,the glue tab 16 and the outer portion 29 of the second end flap areprovided with spots of adhesive 38, 39 respectively by means of a rollerin known manner. As a final operation, the third side wall portion 15 isfolded over about the score 14 to overlie the second side wall portion13. Upon this final folding the glue tab 16 is adhered to the third sidewall portion 15 and the outer portion *29 of the second end flap 25 isadhered to part of the outer surface of the triangular part 19 of thefirst end flap. The bottom end of the carton in its final flattened formis shown in FIGURE 4.

The flattened carton 'of FIGURE 4 is erected by applying pressure in thedirections of the arrows 40 and 4-1 in FIGURE 5 to the scores 14 and 17.Asthe side wall portion 10 flattens it pushes apart the remote edges ofthe second and third side wall portions 13 and -15 which pivot about thescore 14 until the carton assumes a triangular cross-section. As theside wall portions 13 and 15 move apart, the outer portion 29 of thesecond end flap which is secured to the triangular part '19 of r2,996,234 r F the first end flap will draw the triangular part into aposition in which it is perpendicular to the side wall portions. Whenthe carton is fully erected, as shown in FIGURE 6, the second end flap25 is outside and parallel to the triangular part 19 of the first endflap and both end flaps are perpendicular to the side wall portions.

As the triangular part 1 9 is moved into a position in which it .isperpendicular to the side wall portions, the first and second extensions21 and 23 will come into contact with the third and first sidewallportions 15 and respectively and will be bent until they lieperpendicular to the triangular portion 19 as shown in FIGURE 6.Referring now to this figure, it will be seen that the first extension21 has been received in the recess 31 at the end of the glue tab 16. Inthis position, the edges 34, 35 of the first extension 21 mate with theedges 33 and 32 respectively of the recess 31. The first extension 21 ismaintained in the recess 31 by the natural resilience of the paperboardand once it has been received in the recess it will be seen that it willprevent the triangular part 19 of the first end flap from movinginwardly towards the interior of the carton.

The triangular part 19 is dimensioned to substantially close the end ofthe carton and therefore it holds the side walls in their open positionso long as it is maintained perpendicular to the walls by means of thelock constituted by the recess 31 and the extension 21. In the fullyerected position of FIGURE 6, the second extension 23 is pressed againstthe first side wall portion 10 and forms a seal against that side wallportion thus preventing the escape of the contents of the carton shouldthese be of a pulverulent or similar nature. Moreover, the extension 23helps to flatten the side wall portion 10 as the carton is erected. Thesecond end flap is cut away at 36 so that, as the blank is assembled,the end flap will not be caused to overlie the glue tab 16 to an extentsufficient to prevent erection of the carton.

It will be seen that the blank of FIGURE 1 may be easily assembled an aconventional right-angled gluer in which, as the blank is being passedin one direction, the end flaps may be folded in directionsperpendicular to the direction of movement and, as the blank is moved ina second direction the side wall portions may be folded in to completethe assembly of the carton. Moreover, when the carton is assembled, thebottom is locked in posit-ion by means of the extension 21 and the notch31 and the bottom of the carton is sealed where it might be likely toleak by means of the second extension 23 of the first end flap. In theembodiment so far described, when the carton is assembled, the inner andouter portions 23, 29 of the second end flap lie susbtantially in thesame plane which makes for a very neat appearance. \As mentioned above,any convenient top closure may be provided.

Referring now to FIGURE 7, this shows an alternative step in a method offolding the blank of FIGURE 1 to make a triangular carton similar tothat hereinbefore described. FIGURE 7 indicates a stage of folding ofthe blank corresponding to the stage shown in FIG- URE 3 for the firstembodiment. The only differences between. the two stages is that inFIGURE 7 the outer portion 29 of the second end tlap 25 has not beenfolded to overlie the inner portion 28 of the end flap and thus remainsin the same plane therewith. Glue spots 42 are applied to the outerportion 29 at the same time as glue spots 38 are applied to the glue tab16 and upon folding over of the third wall portion .15 about the scoreline 14, the outer portion 29 is adhered to the outer surface of thetriangular part 19 of the first end flap. The cut-out 30 in this case isalso provided to clear the glue tab 16 as described in the previousembodiment.

The carton formed by this modified method is erected in the same. way asthe carton previously described, i.e. the score lines 14 and 17 arepushed towards one another. However, due to the diiferent gluing of theouter portion 29 of the second end flap, the second end flap will befolded over on the score 26 when the carton is assembled as shown inFIGURE 8 so that the outer portion 29 of the second end flap liesbetween the inner portion 28 of the second end flap and the triangularpart '19 of the first end flap. The locking of the triangular part 1-9is identical to that previously described.

If the second extension 23 is omitted, the glue tab 16 could be madeintegral with the third side wall portion 15 and in that case theextension 21 would be formed on the edge of the part 19 remote from theglue tab. Also the final assembly step is different in that the thirdside wall portion 15 would be folded over prior to folding of the firstside wall portion 10.

The invention provides a carton blank which may be folded by automaticmachinery, such as a right-angled gluer, to form a collapsibletriangular carton. The carton so made has an end structure whichautomatically locks as the carton is opened and prevents the end flapfrom moving inwardly into the interior of the carton. Moreover, in thepreferred embodiment, the end flap has an extension which preventsseepage of the contents of the carton through the end closure.Furthermore, the invention provides a method whereby a blank accordingto the invention may be folded on an automatic machine to produce thecarton.

It will be understood that the forms of the invention herewith shown anddescribed are preferred examples and that various modifications may becarried out without departing from the spirit of the invention or thescope of the appended claims.

What I claim as my invention is:

1. A carton blank comprising a sheet of paperboard or the like cut andscored to provide first, second and third side wall portions in seriateside-by-side relation, a glue tab integral with one of said first andthird side wall portions and arranged to be secured to the other of saidfirst and third side wall portions when the carton is assembled, a scorebisecting said first side wall portion parallel to the length thereof,first and second end flaps extending from corresponding ends of thesecond and third side wall portions respectively, the first end flapcomprising an equilateral triangular part having as base the end of thesecond side wall portion, and an extension of said triangular partspringing from the edge thereof which is remote from the glue tab, said.extension being adjacent to the apex of the triangular part, the secondend flap being scored: along a line lying. at substantially 30 to theend of the. third side wall portion and intersecting said end adjacentto the score between the second and third side wall portions, and theglue tab having a recess at the .end thereof which is adjacent to saidend flaps, said recess being dimensioned to receive said extension whenthe carton is assembled;

2. A carton blank comprising a sheet of paperboard or the like cut andscored to provide first, second and third side wall portions in seriateside-by-side relation, a glue tab integral. with said first side wallportion and arranged to be secured to the third side wall portion whenthe carton is assembled, a score bisecting said first side Wall portionparallel to the length thereof, first and second end flaps extendingfrom corresponding ends of the second and third side wall portionsrespectively, the first end fiap comprising an equilateral triangularpart having as base the end of the second side wall portion, a firstextension of said. triangular part springing from the edge thereof whichis remote from the glue tab, said extension being adjacent to the apexof the triangular part, and a second extension along said other edge ofthe triangular part and arranged to lie'within: said first side wallportion when the carton: is. assembled, the second. end flap beingscored along a line lying at substantially 30 to the end of the thirdside wall portion and. intersecting said end adjacent to the scorebetween the second and third side wall portions, the glue tab having arecess at the end thereof which is adjacent to said end flaps, saidrecess being dimensioned to receive said first extension when the cartonis assembled.

3. A carton of triangular cross-section comprising first, second andthird side walls, said first side wall being bisected by a scoreparallel to the length of the carton;

a glue tab integral with one of said first and third side walls andsecured to the other of the first and third side walls; a first end flapextending from an end of the second side wall perpendicular thereto andhaving an equilateral triangular part of a size to substantially closeone end of the carton and having as base the end of the second sidewall; a second end flap extending from an end of the third side wallcorresponding to said end of the second side wall, the second end flaplying outside the first end flap and being scored along a line lying atsubstantially 30 to said end of the third side wall whereby said secondend flap is divided into an inner portion lying between said line andsaid end of the third side wall and an outer portion which is secured tothe outer surface of the first end flap; and an extension of saidtriangular par-t adjacent to the apex thereof and extendingperpendicular to said triangular part to lie adjacent to said other ofsaid first and third side walls; said glue tab having, at an end thereofadjacent to said end flaps, a recess dimensioned to receive saidextension, engagement of the extension in the recess preventing movementof the first end flap into the interior of the carton.

4. A carton according to claim 3, wherein the inner and outer portionsof the second end flap lie in substantially the same plane.

5. A carton according to claim 3, wherein the outer portion of thesecond end flap lies between the inner portion of the second end flapand said first end flap.

6. A carton of triangular cross-section comprising first, second andthird side walls, said first side wall being bisected by a scoreparallel to the length of the carton; a

glue tab integral with the first side wall and secured to the third sidewall; a first end flap extending froman end of the second side wallperpendicular thereto and having an equilateral triangular part of asize to substantially close one end of the carton and having as base theend of the second side wall; a second end flap extending from an end ofthe third side Wall corresponding to said end of the second side wall,the second end flap lying outside the first end flap and being scoredalong a line lying at substantially 30 to said end of the third sidewall whereby said second end flap is divided into an inner portion lyingbetween said line and said end of the third side wall and an outerportion which is secured to the outer surface of the first end flap; afirst extension of said triangular part adjacent to the apex thereof andextending perpendicular :to said triangular part to lie adjacent to thethird side Wall; and a second extension along the edge of saidtriangular part adjacent to the first side wall and extendingperpendicular to said triangular part to lie against said first sidewall; said glue tab having, at an end thereof adjacent to said endflaps, a recess dimensioned to receive said first extension, engagementof the first extension in the recess preventing movement of the firstend flap into the interior of the carton.

7. A carton according to claim 6, wherein the inner and outer portionsof the second end flap lie in substantially the same plane.

8. A carton according to claim 6, wherein the outer portion of thesecond end flap lies between the inner portion of the second end flapand said first end flap.

References Cited in the file of this patent UNITED STATES PATENTS2,411,144 Bergstein Nov. 19, 1946 2,412,546 Waters Dec. 10, 19462,483,464 Johnson Oct. 4, 1949 2,807,403 Joseph Sept. 24, 1957

